Residential heating and cooling are major energy consumers. Heating, which consumes foosil fuel such as gas or oil, or electrical energy, can be reduced by turning down the heat at night and using heavy bed covers or electric blankets to maintain personal comfort while sleeping. The energy requirements, even in the case of electrically heated blankets, have been sharply reduced, since, instead of heating the whole house or several rooms to the required high temperature, the heating duty can be restricted to that of a very small, well-insulated volume, namely the space occupied by the person sleeping, and confined by the mattress at the bottom and the blankets on top. Since the human body generates a certain amount of heat, the only energy input required by the electric blanket heating elements is to make up for the heat lost through the blankets and mattress, in order to maintain a comfortable bed temperature. Depending on the room temperature and the temperature required to achieve a satisfactory personal comfort level, the energy input requirements of the electric blanket may be very low or zero.
On the other hand, for cooling purposes during warm and humid evenings and nights, blankets are of no avail and, in order to achieve an adequate level of comfort when resting or sleeping, the whole house, or at least the bedroom area, has to be cooled by means of air-conditioning, a high energy consumer. The present invention provides a means to achieve a high degree of energy conservation by restricting the necessary cooling requirements only to the bed volume occupied by the person resting or sleeping. Again, this volume is well insulated, minimizing the amount of heat absorbed from the warm outside. The invention, therefore, as will be described, will enable the homeowner to turn down his room or central air conditioner at night to a very low level, or turn it off altogether, yet achieve a high degree of temperature comfort while sleeping under the cooling blanket.
The invention, as will be described, is not restricted to specifically a blanket, nor specifically to a blanket to provide sleeping comfort. The cooled cover can be form-fitted to resemble a garment, such as a jacket or robe, to provide cooling when sitting and working at a desk, watching television, working, or eating. The cooling blanket, as such, can of course be used to cover a sitting or lying person.
Further, the invention, as described, is not restricted to cooling, but can also be used for heating. However, it is distinct from an electric blanket or an electrically heated garment in that the heat supplied by means of a heat pump comes from a source which is separate from the blanket or garment, and is connected to it via a feed and return duct through which the foam heating fluid is circulated. The same device which provides cooling in the summer can supply heating in the winter by a simple reversal of the heat pump from cooling to heating service.
The use of foam to effect the personal cooling and heating achieved by means of the instant invention has a number of distinct advantages. Foam has a reasonable heat capacity, so that the amount of circulating fluid, in the form of said foam, can easily be handled through the required passages without excessive pressure drop and without making any sound. The quantity of circulation required compared to a gas is far less, and much more effective heat transfer is realized. However, the major advantage is that, compared to a liquid, foam is much lighter and will actually not add appreciably to the weight of the blanket. Since blanket or clothing weight is a major comfort consideration, this light-weight feature of circulating foam is an important consideration in the practicality of the overall concept.